2000 v8: exhausted & scratching my head

sgrillak

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hello everybody. i've been lurking around here for a little over 2 years and gotten better help from thia forum than from the local dealers. for that, thank you. with things i've learned here i seem like a ls guru where i live.

now my problem: a while back i got a camshaft position sensor code. it didnt affect the car much, just a slight shake every now & again (i now know those were misfires). i let it go for a month but by then i started getting multiple misfire codes but the car still ran pretty good. one day on my way to work, it stalled but started right back up. ran fine for a couple of days then started running really rough when it reached normal operating temp. it did this for about 2 days when i noticed the pattern. i pulled the codes and got misfires on 5 cylinders as well as bad cats. i drove it to work (only transportation) and on the way home got the dreaded aice chip fault code, the message center told me that the pcm couldn't find TDC. car died out and wouldn't restart. i bought a vcm2. i got some codes related to pcm communications so i pulled the pcm relay, replaced it, and cleaned ALL sockets in ALL fuse boxes as well as all connectors (found a lot of corrosion). i replaced the cmp, ckp, all cops & plugs. car still wouldn't start. i could now communicate with the pcm but the car told me that a theft was detected. i figured the pcm was damaged from the misfires so i replaced it. i programmed everything now the car cranks but won't start. i know the cats are damaged but i pulled the downstream o2 sensors and i get pressure from the holes. i switched to using Forscan (a lot easier to use) for diags and koeo tests now give me b1681 and reading pid data tells me that the cmp is low (not sure what it's supposed to be). after some research i'm thinking the pats transceiver is bad. none of the tests i have run indicate anything wrong with the timing chains but i imagine it could be possible. i will be replacing the pats transceiver this weekend. does anyone have any thoughts/suggestions?
 
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i edited my original post to fix spelling, sentences, and to make it understandable. any help would be greatly appreciated.
 
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sorry about that. it's a 2000 v8 sport. i have a pats transceiver but the weather is starting to get nasty here. i will be doing pinpoint tests in the morning before i install it.
 
B1681 is PATS transceiver signal not received. That would cause a no start. The PATS transceiver module signal is not received by the PCM. Can be caused by the circuits between the PATS transceiver and the PCM or the PATS transceiver itself.

When a valid PATS key is turned to the ON or RUN position the PCM queries the PATS transceiver, it then reads the key code and sends the code to the PCM. The PCM then validates the read code against stored authorized keys. If the codes match, the PCM then enables the starter. If the codes do not match, the starter remains disabled and the vehicle does not start.

On your valid encoded ignition key ring, remove all items like gas card or grocery store, anything with a magnetic strip on it can prevent the transceiver from receiving the signal from the key.

Try another key that is already programmed to that car ... if not you are right in that you'll have to pin test it to be sure the transceiver module isn't done.

Is your red on top of dash PATS light rapidly flashes at this time ?

Is this a flood salvage vehicle ?
 
.. i programmed everything now the car cranks but won't start.

Oh ... that changes things ... if it's allowing the starter to engage it's not your PATS transceiver. At least I didn't think so. Joegr is an expert at these electronic things. PM @joegr attention to this thread for his suggestions.
 
thanks for taking a look. i'll see if joegr will chime in. from what i read in one of the earlier tsb's, the gen 1's can have a pats issue and still crank (tsb dated 01-06-02). it's possible i'm misunderstanding it. there was a pats diag bulletin that stated that also. i'm trying to dig it out.
 
i just checked the pats job aid (ford issued). it Does show that all ls' have starter disable. now that has me really confused, before i changed my pcm i got a p1260. the car still cranked. after i changed the pcm (but before ANY module reprogramming) i got a lot of codes about mismatched pcm and another p1260. which i fully expected. car still cranked. it was after programming that i got the b1681. and the car still cranks....
 
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pats led: when i was getting the p1260 it was blinking rapidly. now it proves out but i have the b1681.
 
I've never ventured here with this issue myself on any LS however I would have thought it would disable the starter so to speak. As in not allow. PATS transceiver signal not received.

Do you have any other keys for this car?
 
yes. i have 3 programmed keys. it does the same with all 3. Reference: - Ford Anti-Theft (PATS)
if you go about half way down this page you'll see the pcm install/pats reset info. if i'm reading it correctly a pats fault, even with starter interupt, will allow a crank but no start condition. if any body else wants to weigh-in feel free. i sprayed starting fluid and it ran making me think pats shut down the injectors.
 
Yeah key would be more like B1600 - PATS Key Transponder Signal is Not Received — Damaged Key or Non-PATS Key

I suppose you could have a look at the 2nd GEN PATS and see if it applies.
Pinpoint Test I: DTC B1681 — The Passive Anti-Theft System (PATS) Transceiver Signal Is Not Received (Not Connected, Damaged, Or Wiring)

as a side note:
The control function is contained in the instrument cluster. This module carries out all of the PATS functions, such as receiving the identification code from the PATS key and controlling the starter enable signal, and communicates with the PCM to enable the engine. The instrument cluster initiates the key interrogation sequence when the PATS key is inserted in the ignition switch and also when the switch is turned to RUN or START.

The PATS module uses the instrument cluster to enable or disable the engine. All elements of PATS must be functional before the engine is allowed to start. If any of the components are not working correctly, the vehicle does not start.

NOTE: If either the instrument cluster or the PCM are installed, both modules require a parameter reset. Failure to carry out the parameter reset to both the instrument cluster and PCM may result in a no-start condition.
 
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It seems odd that it would shut down the fuel, but not the ignition. Are you sure that the fuel pump is okay?
 
hey. thanks for dropping in. the fuel pump is fine. pressure at the rail during cranking is ~50 psi. i did the pinpoint test for the pats transceiver and it was shot so i replaced it. i'm no longer getting the b1681. but i am getting u1262 on the ic and mc. running an osc scope during cranking it shows the ckp is not active (ckp is new). the cmp is showing low (i think it's supposed to show low). i smell fuel after cranking a few times (was not smelling it before).
 

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